International Workers' Day, also known as Labour Day in some countries, is a celebration of labourers and the working classes that is promoted by the international labour movement, socialists, communists or anarchists.

It occurs every year on May Day which is May 1st. It is the day to pay tribute to the Labourers. Without them nothing will complete.

In India, the first Labour Day, or May Day, was celebrated in 1923 in Chennai.

Every year on 24th October, United Nations Day is celebrated to commemorate the day of United Nations formation.

The United Nations is an intergovernmental organization that was tasked to maintain international peace and security, develop friendly relations among nations, achieve international co-operation and be a centre for harmonizing the actions of nations. I was started on 24 October 1945.

National security refers to security of a nation state, including its citizens, economy&institutions, is regarded as a duty of govt. It is celebrated every year on 4th March. The 1st National Security Day observed in the year 1972.